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Medline ® Abstract for Reference 46

of 'Physiology of amniotic fluid volume regulation'

Decreased umbilical orexin-A level is associated with idiopathic polyhydramnios.
Cho GJ, Hong HR, Kim SW, Hong SC, Oh MJ, Kim HJ
Acta Obstet Gynecol Scand. 2015 Mar;94(3):295-300. Epub 2015 Jan 25.
OBJECTIVE: To evaluate the association between orexin-A level and idiopathic polyhydramnios.
DESIGN: Case-control study.
SETTING: Tertiary-level university hospital.
POPULATION: Ten term pregnant women with idiopathic polyhydramnios and, as the control group, 20 pregnant women with normal amniotic fluid levels.
METHODS: Amniotic fluid level was measured at admission for delivery using enzyme-linked immunosorbent assay. Maternal blood was obtained from a cannulated vein immediately before delivery, and umbilical blood was collected at the time of delivery, before the separation of the placenta.
MAIN OUTCOME MEASURES: Maternal and umbilical levels of orexin-A.
RESULTS: Mean umbilical serum orexin-A level was significantly lower than maternal serum orexin-A level. Umbilical serum orexin-A level was positively correlated with maternal serum orexin-A level, but negatively correlated with amniotic fluid index and birthweight. Umbilical serum orexin-A level was lower in the idiopathic polyhydramnios group than in the control group. However, no difference in maternal serum orexin-A level was observed between the two groups.
CONCLUSIONS: Idiopathic polyhydramnios was associated with decreased umbilical serum orexin-A levels. Our results provide evidence that orexin-A expression may be involved in amniotic fluid regulation, causing polyhydramnios by downregulation.
Department of Obstetrics and Gynecology, College of Medicine, Korea University, Seoul, Korea.